Photomask container

ABSTRACT

A container suitable for storing and transporting photomasks and including a container body, a cover, first and second cushions and left and right channels disposed in slots formed in the container body. In one embodiment, the container of this invention is formed in a one-piece design by rotomolding. The cover is subsequently separated from the body and machined so as to provide a slidingly sufficient seal and disposed therein.

RELATED APPLICATIONS

This application is a divisional of application Ser. No. 11/286,696filed Nov. 23, 2005, which claims the benefit of U.S. ProvisionalApplication No. 60/630,907 filed Nov. 24, 20024, each of which is herebyfully incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to containers and, in particular, this inventionrelates to reusable containers for storing and transporting fragiledevices such as photomasks.

BACKGROUND OF THE INVENTION

Typically fragile substrate devices, such as larger photomasks, forexample larger than 24 inches in length, are stored and shipped inprefabricated plastic boxes. Due to their size, these prefabricatedplastic boxes, particularly for photomasks, are relatively expensive tomake and are typically used only a single time. Therefore, it would beadvantageous to the industry to provide containers suitable forphotomasks, or other substrates, that are inexpensive to manufacture,yet protect the product from damage during transport and shipping.

SUMMARY OF THE INVENTION

The container herein is suitable for storing and transporting large,that is having a major dimension of at least 24 inches, photomasks. Inone embodiment, the carrier of this invention is substantially asingular piece, which may be rotationally molded, then machined toseparate the cover from the body. The instant container may be moldedfrom a static dissipative material, such as polyethylene with anelectrical conductor dispersed therein. Upper and lower cushions may bedisposed within the instant container to secure the photomask disposedtherein and to protect the photomask from damage due to mechanicalshock. The upper and lower cushions may be made with a staticdissipative synthetic resin, such as polyethylene foam with anelectrical conductor dispersed therein. Channels may be machined in sideinserts of the instant container to insure that photomasks slide easilyinto and out of the instant container.

There is provided a method for making a container of this invention andsuitable for protectively securing a photomask therewithin, the methodincluding forming a unitary container body, removing portions from twosides of the container body to form slots, inserting channels in theside slots, and forming a cover for the container. The lid or cover ispreferably part of the original molded “body preform” which is cut intoportions one or more times to form the body or container portion with anopen end and the cover. The container body and/or the lid may be formedfrom a synthetic resin such as polyethylene, the polyethylene optionallycomprising an electrostatically dissipative material. The slots may beformed by machining. The channels may be welded in the slots by a streamof heated air. Alternatively, the mold can have metal inserts to formthe channels during the mold process.

There is also provided a method of disposing a photomask in a container,in which the container has a generally integral body having channelsinsertably sealed to the body, the method comprising inserting thephotomask into a cavity of the body such that edges of the photomaskcontact the channels; and sealing the container with a lid.

It is a feature of the instant invention to provide a molded, one-piececontainer. It is an advantage of the foregoing feature that the providedcontainer is more cheaply made and stronger, e.g., by the absence ofwelded seams.

It is a feature of this invention to provide one embodiment of themanufactured from polyethylene. It is an advantage of the foregoingfeature that the instant container is more readily recycled.

It is yet another feature of this invention that the provided containeris made using wide tolerance rotomolded synthetic resin with insertsfrom narrow tolerance-machine bar stock (e.g., polyethylene) to meet thefunctional requirements presented. It is an advantage of the foregoingfeature that utilization of the bar stock provides a suitable containerat a significantly lower cost than the fabricated designs of the priorart.

It is a feature of the instant invention that one embodiment thereof maybe substantially entirely constructed from electrostatically dissipativematerial. It is an advantage of the foregoing feature that damage to thecontents of the container due to electrostatic discharge may be greatlyminimized or essentially eliminated.

It is yet another feature of this invention that the rotomolding processand design may be used to create a singularly uni-dimensional container.It is an advantage of the foregoing feature that the container createdthereby may be cut to adjust the height thereof thereby customizinglengths to fit photomasks of varying heights and dimensions.

It is yet another feature of this invention that the body and lid of theprovided container may be molded from the same tool. It is an advantageof the foregoing feature that the provided container is constructed at agreatly reduced cost.

It is yet another feature of this invention that containers may be madeby a protocol of welding synthetic resins by a heated air stream. It isan advantage of the foregoing feature that containers for such items asphotomasks and semiconductor wafers made by such a welding protocol aremade more cheaply and are potentially stronger than containers madeotherwise.

In certain embodiments the channels providing the grooves for supportingthe photomask or other substrate can be inserted in the mold before therotational molding process. Such inserts can have metal blanks toprotect a preformed channel to be subsequently removed and can be madeof a plastic or other compatible material that has a higher melttemperature that the resin used for formation of the container body.

These and other features and advantages of the instant invention willbecome apparent from the description which follows, when considered inview of the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a perspective view of the container of this invention.

FIG. 1B is a front view of the container of FIG. 1A.

FIG. 2 is a front view of a body preform for making the containerherein.

FIG. 3 is a side elevational view of the container of FIG. 1.

FIG. 3A is a side view of a body preform of the container of FIG. 1A.

FIG. 3B is a side view showing portions of the body preform severed toform the present container.

FIG. 3C is a side view of the present container.

FIG. 3D is a side view showing a closeup cutaway portion of the cover ofFIG. 3C.

FIG. 4 is a cross sectional view of the container of FIG. 3 along lines4-4.

FIG. 5A is a cross sectional view of the container of FIG. 1B alonglines 5A-5A.

FIG. 5B is a top view of the cover of the instant container.

FIG. 6 is a cross sectional perspective view of the container similar tothe view of FIG. 4.

FIG. 7 is an exploded view of the container of FIG. 1.

FIG. 8 is a perspective view of a mold for molding the body preform.

It is understood that the above-described figures are only illustrativeof the present invention and are not contemplated to limit the scopethereof.

DETAILED DESCRIPTION OF THE DRAWINGS

References to relative terms such as upper and lower, front and back,left and right, or the like, are intended for convenience of descriptionand are not contemplated to limit the present invention, or itscomponents, to any one positional or special orientation. All dimensionsdepicted in the figures may vary with a potential design and theintended use of a specific embodiment of this invention withoutdeparting from the scope thereof. Although the container is depictedupright with a height being the major dimension, in use the containermay be primarily used with the major dimension and the photomask thereinin the horizontal.

Each of the additional figures and methods disclosed herein may be usedseparately, or in conjunction with other features and methods, toprovide improved containers and methods for making and using the same.Therefore, combinations of features and methods disclosed herein may notbe necessary to practice the invention in its broadest sense and areinstead disclosed merely to particularly describe representative andpreferred embodiments of the instant invention.

One embodiment of the container of this invention is depicted in thefigures generally at 10 and may include a body 104 or container portion,a cover 106, a closed bottom 107 with a bottom wall 109, respectivefirst (upper) and second (lower) supports configured as cushions 108 and110, first (left) and second (right) inserts 112 and 114 with channels113. The foregoing elements cooperating to provide a container forsafely and securely storing and transporting a photomask 116. Thecontainer has a height h, a depth d, and a width w.

The body 104, in turn, has respective front and back walls 120 and 122with exterior surfaces 121, 123 and respective left and right sidewalls124 and 126 with exterior surfaces 125 and 127. Left and right slots 128and 130, respectively, may be machined or otherwise formed in therespective left and right sides 124 and 126. The inserts 112 and 114 arethen placed in the left and right apertures configured as slots 128 and130 and may be secured therein by being welded in place at weldments131. In one method the inserts 112 and 114 are secured within the leftand right slots 128 and 130 by a form of welding, in which a syntheticresin is melted in place by a stream of heated air. Other methodssecuring the channels 112 and 114 in the slots 128 and 130 include sonicwelding and use of bonding agents or conventional fasteners such asscrews, bolts, rivets. Moreover, the instant invention is contemplatedto include processes which utilize welding a synthetic resin by means ofa heated air stream and which are for manufacturing other substratecontainers such as containers for semiconductor wafers.

When being made, the container 100 is unitarily formed, then the cover106 is separated from the remainder of the container 100 and machined asappropriate so as to slidingly fit over the body portion in a snug,optionally air tight, manner. The other end of the body 104 includes anenlarged base 132. The base 132 provides stability and shock resistanceto the container 100 during transport and use. By way of illustrationand not limitation and referring to FIGS. 2, 3A-D, a body preform 133made by molding. As shown in FIGS. 2 and 3A, the body preform hasrespective body, cover, and base portions 142, 144, and 148. The bodypreform is then cut along two planes indicated by lines 150 and 152 toform the instant container 100 with the body 104, cover 106, and base132. The cut at 152 may be positioned to provide the container sized asdesired in length. The portion of the body portion 142 completelysevered from the remainder thereof (between the planes 150 and 152) isdiscarded. The cover 106, optionally machined to provide beveling, canthen be disposed over the body 104 as indicated by the arrow 154.Referring now to FIG. 3D, the cover 106, when disposed as shown, ideallyfits snugly over the body 104, thereby providing an air-tight sealprotecting the enclosed photomask from ambient contamination andretaining the enclosed photomask in the container 100.

Because of the molded one-piece design, the instant container is madeless expensively and is stronger than many containers of the prior art.One reason the instant container is stronger and more durable is thatthe instant container has welded seams. Additionally, all components ofthe instant container may be manufactured from a synthetic resin such aspolyethylene. If polyethylene is utilized, the instant container is morereadily recycled. Manufacturing the instant container combines the useof wide tolerance rotomolding with narrow-tolerance machinedpolyethylene bar stock to meet the functional requirements of thechannels 112 and 114 at a significantly lower cost than a design,wherein the channels are separately molded. Additionally, the molded-ingraphics optionally present are advantageous because they are not easilyremoved or scratched as opposed to the use of other labels, which aremore easily scratched off or removed. Additionally, the entire containermay be made from an electrostatically dissipative material, therebypreventing damage to the photomask stored and transported therein.

Referring to FIG. 8, a mold 160 suitable for rotationally molding thebody preform 133 is illustrated. The mold has two halves 162, 163 insidesurfaces 165 defining a cavity 166 having cavity portions 170, and anadjacent cavity midportion 172.

Resin, for example in bead form, is put into the open mold. The mold isclosed, heated and rotated to disperse molten resin to cover the insidesurfaces. The heat is removed, the mold allowed to cool, the mold isopened and the body preform is removed. The top cover is severed, thecontainer portion cut to a desired size, and the slots in the sidewallsmay be cut. The inserts, with channels machined or otherwise in place onthe inserts, are attached to the slots, preferably by welding.

Additionally suitable graphics 200, such as graphics on a thin filmsubstrate may be put in the cavity on one of the surfaces, such as 180on FIG. 8, and affixed thereto. Then the molten resin can overmold thethin film and securely fix the graphics in place. Additionally, insertsmay be secured in the mold such as at 182 having channels therein as analternative to the cutting of slots and welding the inserts therein. Inthis option, the insert would preferably be formed of a polymer or othermaterial that has a melt temperature higher than the resin being addedto the mold for forming the body preform. Additionally, blanks may benecessary to cover the channel during the molding. Such can besubsequently removed after the plastic has hardened.

Because numerous modifications of this invention may be made withoutdeparting from the spirit thereof, the scope of the invention is not tobe limited to the embodiments illustrated and described. Rather, thescope of the invention is to be determined by the appended claims andtheir equivalents.

1. A container for transporting photomasks in combination with aphotomask, the photomask being generally rectangular and planar andhaving two ends, two sides, and a thickness, the container comprising:an elongate polymer container portion having a closed top wall with anexterior surface, a closed bottom wall with a exterior surface, a closedend and an open front, a pair of opposite side walls each with anexterior surface, each of the pair of sidewalls comprising an elongatepolymer insert with an channel extending lengthwise and secured into thesidewall by weldments, the photomask positioned in the channels, a coverclosing the open end and partially extending over and engaging theexterior surface of the top wall, the exterior surface of the bottomwall, and the exterior surfaces of the two sidewalls, and a pair of endsupports positioned at each end of the photomask in the container, theend supports engaging and securing the photomask in position when thecover closes the open end.
 2. The combination of claim 1 wherein thecontainer portion and the side wall inserts are comprised ofpolyethelene.
 3. The combination of claim 1 wherein the end supports arecomprised of a foamed polymer.
 4. The combination of claim 1 wherein thephotomask has a length of at least 24 inches.
 5. A container fortransporting photomasks, the photomask being generally rectangular andplanar and having two ends, two sides, and a thickness, the containercomprising: an elongate polymer container portion having a closed topwall with an exterior surface, a closed bottom wall with a exteriorsurface, a closed end and an open front, a pair of opposite side wallseach with an exterior surface, each of the pair of sidewalls comprisingan elongate polymer insert with an channel extending lengthwise andsecured into the sidewall by weldments, the photomask positioned in thechannels, a cover closing the open end and partially extending over andengaging the exterior surface of the top wall, the exterior surface ofthe bottom wall, and the exterior surfaces of the two sidewalls, and apair of end supports positioned at each end of the photomask in thecontainer, the end supports engaging and securing the photomask inposition when the cover closes the open end.
 6. The container of claim 1wherein the container portion and the side wall inserts are comprised ofpolyethelene.
 7. The container of claim 1 wherein the end supports arecomprised of a foamed polymer.
 8. The container of claim 1 wherein thephotomask has a length of at least 24 inches.